Molybdenite

160.07

161.85000

215-263-9

ZC8B4P503V

LEAD-GRAY, LUSTROUS POWDER|Black luster, hexagonal crystals

64.18000

1.29640

powder

5.06 g/mL at 25ºC(lit.)

2375 °C

450 deg C, sublimes

soluble in sulfuric and nitric acid

Under strongly oxidizing conditions, is oxidized to molybdic trioxide, MoO3.

22-24/25

QA4697000

Stable under ordinary conditions

P201, P202, P281, P308+P313, P405, P501

H350

SRP: At the time of review, criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices.

HYDROGEN PEROXIDE REACTS VIGOROUSLY WITH ... MOLYBDENUM DISULFIDE ...|Mixtures of potassium nitrate with .... molybdenum disulfide are ... detonable.|/Incompatible with/ strong oxidizers. /Molybdenum, insoluble compounds, (as Mo)/

Nat'l Research Council Canada; Data Sheets on Selected Toxic Elements (1982) NRCC No. 19252|USEPA, Office of Drinking Water; Criteria Document (Draft): Molybdenum (1985)

|Danger|H350 (100%): May cause cancer [Danger Carcinogenicity]|P201, P202, P281, P308+P313, P405, and P501|Aggregated GHS information provided by 4 companies from 2 notifications to the ECHA C&L Inventory.|Warning|H315 (19.94%): Causes skin irritation [Warning Skin corrosion/irritation]|P261, P264, P271, P280, P302+P352, P304+P312, P304+P340, P305+P351+P338, P312, P321, P332+P313, P337+P313, P362, P403+P233, P405, and P501|Aggregated GHS information provided by 1517 companies from 13 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.|Not Classified

Respirators may be used when engineering and work practice controls are not technically feasible, when such controls are in the process of being installed, or when they fail and need to be supplemented. Respirators may also be used for operations which require entry into tanks or closed vessels, and in emergency situations. If the use of respirators is necessary, the only respirators permitted are those that have been approved by the Mine Safety and Health Administration (formerly Mining Enforcement and Safety Administration) or by the National Institute for Occupational Safety and Health. /Soluble Molybdenum cmpd (as Molybdenum); Molybdenum and insoluble molybdenum cmpd/|Respirator selection: Upper limit devices recommended by ACGIH: Up to 50 mg/cu m: Any dust and mist respirator; up to 100 mg/cu m: any dust and mist respirator except single-use and quarter mask respirators or any supplied air respirator or any self contained breathing apparatus; up to 250 mg/cu m: any powered air purifying respirator with a dust and mist filter or any supplied air respirator operated in a continuous flow mode; up to 500 mg/cu m: any air purifying full facepiece respirator with a high efficiency particulate filter or any powered air purifying respirator with a tight fitting facepiece and a high efficiency particulate filter or any supplied air respirator with a tight fitting facepiece operated in a continuous flow mode or any self contained breathing apparatus with a full facepiece or any supplied air respirator with a full facepiece; up to 7500 mg/cu m: any supplied air respirator with a half mask and operated in a pressure-demand or other positive pressure mode; Emergency or planned entry in unknown concentration or IDLH conditions: any self contained breathing apparatus with a full facepiece and operated in a pressure demand or other positive pressure mode or any supplied air respirator with a full facepiece and operated in a pressure demand or other positive pressure mode in combination with an auxiliary self contained breathing apparatus operated in pressure demand or other positive pressure mode; Escape: any air purifying full facepiece respirator with cartridge(s) providing protection against the compound of concern and having a high efficiency particulate filter or any appropriate escape type self contained breathing apparatus. /Molybdenum, insoluble compounds (as Mo)/

... A complete respiratory protection program should be instituted which incl regular training, maintenance, inspection, cleaning, and evaluation. /Sol Molybdenum compounds (as Mo); Molybdenum and insoluble molybdenum compounds/

Permissible Exposure Limit: Table Z-1 8-hr Time Weighted Avg: 15 mg/cu m. /Molybdenum insoluble compounds, as Mo, total dust/|Vacated 1989 OSHA PEL TWA 10 mg/cu m is still enforced in some states. /Molybdenum insoluble compounds, as Mo/

Molybdenum in normal soil seems to vary between 0.1 and 10 mg/kg. In mining areas and near Molybdenum-emitting industries, considerably higher values have been reported. /Molybdenum/

In ambient air in urban areas, molybdenum ranged from 0.01 to 0.03 ug/cu m and in non urban areas it varied between 0.001 and 0.0032 ug/cu m. /Molybdenum/

In persons with impaired pulmonary function, especially those with obstructive airway diseases, the breathing of insoluble molybdenum compounds might cause exacerbation of symptoms due to their irritant properties. /Molybdenum and insoluble molybdenum compounds/

Occurs as the mineral molybdenite, which is the principal source of molybdenum.|Both suspended insoluble molybdenum sulfide and soluble molybdates are present in streams that drain areas where molybdenum ore is mined and processed, especially in Colorado and New Mexico.

... THE FATE OF MOLYBDENUM IN A COAL FIRED ELECTRIC POWER PLANT IN COLORADO /WAS STUDIED/ ... RESULTS SHOWED THAT MOLYBDENUM FROM COAL IS ... ENRICHED IN FLY ASH LEAVING COAL FIRED POWER PLANT IN STACK GASES, (EVEN AFTER TREATMENT WITH ELECTROSTATIC PRECIPITATORS AND WET SCRUBBERS), BUT ... DECREASED IN BOTTOM ASH. ENRICHMENT IN FLY ASH APPEARS TO BE RELATED TO THE VOLATILITY OF MOLYBDENUM & ITS ADSORPTION ON FINE PARTICLES. MOLYBDENUM THAT ESCAPES IN PARTICULATE MATTER IN STACK GASES MAY BE EXPECTED TO SETTLE TO EARTH AND ENRICH SOIL, PLANTS, & WATER ... /MOLYBDENUM/|Molybdenum in sewage sludge was found to vary between 2 and 30 mg/kg dry weight. /Molybdenum/

INDUST EXPOSURES RELATED TO PRODN & FABRICATION OF MOLYBDENUM PRODUCTS ARE TO DUSTS & FUME OF MOLYBDENUM, ITS OXIDES & SULFIDES CHIEFLY FROM ELECTRIC FURNACE OR OTHER HIGH TEMP TREATMENT. ... SPRAYING OF MOLYBDENUM MAY PROVIDE HAZARD; AND LOSS OF MOLYBDENUM CATALYSTS TO THE AIR ADDS TO THE METAL BURDEN OF CONTAMINATED ATMOSPHERES.|... Common operations in which exposure to soluble molybdenum compounds may occur ... /are/: liberation during rolling of hot billets in processing molybdenum steel; for use as electrodes; during welding operations; use as chemical reagent for lab analyses; in petroleum refining and chemical processing; as an intermediate in the manufacture of corrosion inhibitors; use as coloring agents for enamels and ceramic glazes; agricultural chemicals; use in electroplating process; use in formulation of corrosion inhibitors for aqueous systems; pigments for paints, lacquers, and coloring animal fibers and hair; use in enamel processes for adherence of vitreous coatings to ceramics and metal; use in leather and skin tanning; use as chlorination catalysts; in fire retardant resins; as a brazing flux and as an intermediate for organo metallic compunds; use in photography; ion exchange processes and formulation of plastics and adhesives; as a catalyst in desulfurization of gasoline, use as a reagent for determination of phosphorus and lead. /Soluble molybdenum compounds (as molybdenum)/

Humans: total body burden 9.3 mg amount in skeleton: 5 mg amount in liver: 2 mg kidney: 0.9-3.1 mg Mo/kg liver: 1.3-5.8 mg Mo/kg muscle: 0.018 mg Mo/kg bone: 0.7 mg Mo/kg hair: 0.06-0.2 mg Mo/kg nail: 0.15-16 mg Mo/kg whole blood: 0.001 mg Mo/kg.

Determination of molybdenum in tissues (lung, liver, kidney, spleen, bone) of guinea pigs following 25 days of inhalation of subLD50 doses of the sulfide, the dust and fume of the trioxide, and calcium molybdate showed rather uniform distribution in the tissues, incl bone, for all substances at the end of the exposure. Values from 10 to 60 ug/10 g fresh tissue were common for all substances except molybdate trioxide and calcium molybdate dusts, which were higher by a two to four fold factor in the kidney, lung, spleen, and bone. Other exceptions were high lung retentions (40 and 18 times, respectively) for the sulfide and molybdate over that by other tissues according to the thiocyanate method of analysis.|... LARGE AMT /OF MOLYBDENUM/ TEND TO ACCUMULATE IN LIVER. /MOLYBDENUM/

CHIEF CMPD OF MOLYBDENUM ENCOUNTERED IN INDUSTRIAL EXPOSURE (ESP IN MINING) IS SULFIDE ...|EXPOSURE TO MOLYBDENUM DISULFIDE LUBRICANT SPRAY ... MAY ... PROVE HAZARDOUS TO HEALTH. INSOL MOLYBDENUM CMPD SUCH AS MOLYBDENUM DISULFIDE ... ARE CHARACTERIZED BY LOW TOXICITY ... DERMATITIS FROM CONTACT WITH MOLYBDENUM DISULFIDE IS UNKNOWN.|... MOLYBDENUM CMPD EXHIBIT A LOW ORDER OF TOXICITY, BUT ... SOME DIFFERENCES IN TOXICITY MAY BE ASCRIBED TO DIFFERENT COMPOUNDS; THE TRIOXIDE AND AMMONIUM MOLYBDATE WERE MORE TOXIC THAN THE ORE MOLYBDENITE, THE METAL OR THE DIOXIDE. /MOLYBDENUM CMPD/|MOLYBDENUM INTOXICATION DEPENDS UPON THE CHEM FORM & DOSE & IS INFLUENCED BY SULFATE, COPPER (2+), ZINC (2+), LEAD (2+), PROTEIN INTAKE, FORM & AMT OF COPPER, & ORGANIC SULFUR, SUCH AS CYSTINE & METHIONINE IN THE BODY. /MOLYBDENUM/

Mo3S4

A small portion of molybdenite concentrate production is purified to yield lubricant grade molybdenum disulfide.

All other basic inorganic chemical manufacturing|Molybdenum sulfide (MoS2): ACTIVE|Molybdenite concn contains about 90% molybdenum disulfide. The remainder is primarily silica. The concentrate is roasted to remove the sulfur and convert the sulfide to oxide.|LAB PREPN: BELL, HERFERT, J AM CHEM SOC 79, 3351 (1957).

NIOSH 7300: Analyte: molybdenum; Matrix: air; Technique: inductively coupled argon plasma, atomic emission spectroscopy; Wavelength: 281.6 nm; Range: 2.5-1000 ug/sample; LOD (Estimated limit of detection): 1 ug per sample; Sensitivity: 0.18 ug/ml; Precision: (relative std deviation): 0.023 @ 2.5 ug/filter, 0.049 @ 1000 ug/filter; Interferences: spectral, minimized by wavelength selection, interelement correction factors and background correction /Elements, molybdenum/|EPA Method 200.7: An Inductively Coupled Plasma-Atomic Emission Spectrophotmetric method for the determination of dissolved, suspended, or total elements in drinking water, surface water, and domestic and industrial wastewaters, is described. Molybdate is analyzed at a wavelength of 202.030 nm and has an estimated detection limit of 8 ug/l. /Total molybdenum/|Direct Aspiration Atomic Absorption Spectrometry is used for the determination of molybdate. Using nitrous oxide acetylene as the flame gas at a wavelength of 313.3 nm, the detection limit is 0.1 mg/l, with a sensitivity of 0.5 mg/l, at an optimum concentration range of 1-20 mg/l. /Total molybdenum/|Analysis (detection limit): polarography: 0.01 mg Mo/kg colorimetry (thiocyanate): 0.1 mg Mo/kg neutron activation: 3 ng atomic absorption (N2O/C2 H2 flames): 0.02 mg Mo/l plasma-emission spectrometry: 0.002 mg Mo/kg spark-source mass spectrometry: 0.3 ng. /Total molybdenum/